Stone Is Stuck In Urethra Does Anyone Know What May Be Wrong With My Guinea Pig?

Does anyone know what may be wrong with my guinea pig? - stone is stuck in urethra

3 weeks ago I noticed blood in the urine leads directly to the veterans, in which he) received an injection of antibiotics (and medication to take home. The blood is gone, but still makes a slight squeak when you allow the bathroom was and today I've noticed an obscure plug the urethra to the outside, about 1 cm long. Of course, I go back to the veterans, but does not seem to know much about Guinea Pigs. Is this a sign of bladder stones or crystals in the bladder? If anyone has an idea, please let me know how it affects me.